package com.dailywork.basepro.thread.safety;

public class SequenceNumber {

    private static ThreadLocal<Integer> seqNum =
            new ThreadLocal<Integer>() {
                @Override
                public Integer initialValue() {
                    return 0;
                }
            };

    public int getNextNum() {
        seqNum.set(seqNum.get() + 1);
        return seqNum.get();
    }

    public static void main(String[] args) {
        SequenceNumber sn = new SequenceNumber();

        TestClient t1 = new TestClient(sn);

        TestClient t2 = new TestClient(sn);

        TestClient t3 = new TestClient(sn);

        t1.start();

        t2.start();

        t3.start();
    }

    public static class TestClient extends Thread {

        private SequenceNumber sn;

        public TestClient(SequenceNumber sn) {
            this.sn = sn;
        }

        @Override
        public void run() {
            for (int i = 0; i < 3; i++) {
                System.out.println(
                        "[Thread-" + Thread.currentThread().getName() + "]sn [" + sn.getNextNum() + "] ");
            }
        }
    }
}
